linux/include/asm-i386/smp.h
Jeremy Fitzhardinge 7c3576d261 [PATCH] i386: Convert PDA into the percpu section
Currently x86 (similar to x84-64) has a special per-cpu structure
called "i386_pda" which can be easily and efficiently referenced via
the %fs register.  An ELF section is more flexible than a structure,
allowing any piece of code to use this area.  Indeed, such a section
already exists: the per-cpu area.

So this patch:
(1) Removes the PDA and uses per-cpu variables for each current member.
(2) Replaces the __KERNEL_PDA segment with __KERNEL_PERCPU.
(3) Creates a per-cpu mirror of __per_cpu_offset called this_cpu_off, which
    can be used to calculate addresses for this CPU's variables.
(4) Simplifies startup, because %fs doesn't need to be loaded with a
    special segment at early boot; it can be deferred until the first
    percpu area is allocated (or never for UP).

The result is less code and one less x86-specific concept.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
2007-05-02 19:27:16 +02:00

171 lines
3.9 KiB
C

#ifndef __ASM_SMP_H
#define __ASM_SMP_H
/*
* We need the APIC definitions automatically as part of 'smp.h'
*/
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/cpumask.h>
#endif
#if defined(CONFIG_X86_LOCAL_APIC) && !defined(__ASSEMBLY__)
#include <asm/bitops.h>
#include <asm/mpspec.h>
#include <asm/apic.h>
#ifdef CONFIG_X86_IO_APIC
#include <asm/io_apic.h>
#endif
#endif
#define BAD_APICID 0xFFu
#ifdef CONFIG_SMP
#ifndef __ASSEMBLY__
/*
* Private routines/data
*/
extern void smp_alloc_memory(void);
extern int pic_mode;
extern int smp_num_siblings;
extern cpumask_t cpu_sibling_map[];
extern cpumask_t cpu_core_map[];
extern void (*mtrr_hook) (void);
extern void zap_low_mappings (void);
extern void lock_ipi_call_lock(void);
extern void unlock_ipi_call_lock(void);
#define MAX_APICID 256
extern u8 x86_cpu_to_apicid[];
#define cpu_physical_id(cpu) x86_cpu_to_apicid[cpu]
#ifdef CONFIG_HOTPLUG_CPU
extern void cpu_exit_clear(void);
extern void cpu_uninit(void);
#endif
struct smp_ops
{
void (*smp_prepare_boot_cpu)(void);
void (*smp_prepare_cpus)(unsigned max_cpus);
int (*cpu_up)(unsigned cpu);
void (*smp_cpus_done)(unsigned max_cpus);
void (*smp_send_stop)(void);
void (*smp_send_reschedule)(int cpu);
int (*smp_call_function_mask)(cpumask_t mask,
void (*func)(void *info), void *info,
int wait);
};
extern struct smp_ops smp_ops;
static inline void smp_prepare_boot_cpu(void)
{
smp_ops.smp_prepare_boot_cpu();
}
static inline void smp_prepare_cpus(unsigned int max_cpus)
{
smp_ops.smp_prepare_cpus(max_cpus);
}
static inline int __cpu_up(unsigned int cpu)
{
return smp_ops.cpu_up(cpu);
}
static inline void smp_cpus_done(unsigned int max_cpus)
{
smp_ops.smp_cpus_done(max_cpus);
}
static inline void smp_send_stop(void)
{
smp_ops.smp_send_stop();
}
static inline void smp_send_reschedule(int cpu)
{
smp_ops.smp_send_reschedule(cpu);
}
static inline int smp_call_function_mask(cpumask_t mask,
void (*func) (void *info), void *info,
int wait)
{
return smp_ops.smp_call_function_mask(mask, func, info, wait);
}
void native_smp_prepare_boot_cpu(void);
void native_smp_prepare_cpus(unsigned int max_cpus);
int native_cpu_up(unsigned int cpunum);
void native_smp_cpus_done(unsigned int max_cpus);
#ifndef CONFIG_PARAVIRT
#define startup_ipi_hook(phys_apicid, start_eip, start_esp) \
do { } while (0)
#endif
/*
* This function is needed by all SMP systems. It must _always_ be valid
* from the initial startup. We map APIC_BASE very early in page_setup(),
* so this is correct in the x86 case.
*/
DECLARE_PER_CPU(int, cpu_number);
#define raw_smp_processor_id() (x86_read_percpu(cpu_number))
extern cpumask_t cpu_callout_map;
extern cpumask_t cpu_callin_map;
extern cpumask_t cpu_possible_map;
/* We don't mark CPUs online until __cpu_up(), so we need another measure */
static inline int num_booting_cpus(void)
{
return cpus_weight(cpu_callout_map);
}
#ifdef CONFIG_X86_LOCAL_APIC
#ifdef APIC_DEFINITION
extern int hard_smp_processor_id(void);
#else
#include <mach_apicdef.h>
static inline int hard_smp_processor_id(void)
{
/* we don't want to mark this access volatile - bad code generation */
return GET_APIC_ID(*(unsigned long *)(APIC_BASE+APIC_ID));
}
#endif
#endif
extern int safe_smp_processor_id(void);
extern int __cpu_disable(void);
extern void __cpu_die(unsigned int cpu);
extern unsigned int num_processors;
#endif /* !__ASSEMBLY__ */
#else /* CONFIG_SMP */
#define safe_smp_processor_id() 0
#define cpu_physical_id(cpu) boot_cpu_physical_apicid
#define NO_PROC_ID 0xFF /* No processor magic marker */
#endif
#ifndef __ASSEMBLY__
extern u8 apicid_2_node[];
#ifdef CONFIG_X86_LOCAL_APIC
static __inline int logical_smp_processor_id(void)
{
/* we don't want to mark this access volatile - bad code generation */
return GET_APIC_LOGICAL_ID(*(unsigned long *)(APIC_BASE+APIC_LDR));
}
#endif
#endif
#endif